When I arrived at EPFL the project I am working on was struggling to function. We are developing hydrogels from Polydimethylsiloxide (PDMS) that will be used for microfluidics and studying stem cell progeny behavior. The PDMS formed into a square (by injecting the silicone into a mold) with sides of about 1/2". Small channels are molded into the face of the chip creating what could be described as a microscopic plumbing system. The channels range from 12 to 24 micrometers in diameter and are between 125 and 1000 micrometers long, depending on the chip, which means that all of our work is done under a microscope so we can actually look at these channels. I realize the description is fairly ambiguous, but I will post images so you can see when I'm at EPFL, I have none on my computer.
The channels are formed in a series of switchbacks winding parallel to each other. Near one end there are small "traps" notched out that act as shortcuts for the fluids to move through the channels. We will eventually be flowing solutions of stem cells in medium through the system and the cells will be caught individually in these traps.
Now I will explain the use/purpose of this. Generally when studying stem cell populations it is pretty much impossible to observe the variation in differentiation from one cell to the next since they are all cultured in clusters. This technique will be used to isolate the stem cells individually so you can observe each individual cells differentation and the daughter cell's lineage. This is important for really understanding the behavior of individual stem cells and signaling cues. So, the place where we are in the project is still analyzing the characteristics of our channels when fluids are flushed through them. We have had many problems with this so far, specifically with dust (or whatever type) particles. The traps in our channels are less than 12 micrometers wide, which means that any particle that happens to get into our PDMS will clog our plumbing and make our chip useless. We have been fighting this for about two weeks now and I have finally made some progress on cleaning the chips and making them more reliable. When I started, nearly every chip would clog before we could gather quantitative measurements. Now we are nearly at a 66% success rate. Hopefully this will continue to improve as I try new methods to clean and keep the chips sterile.
I promise, this will all make much more sense when I post a photo of the chip under the microscope haha.
So, until then, I will move onto the Swiss life.
Since I have been here I have spent a couple of weekends in Lausanne, going to ouchy to read by the lake and seeing festivals. Three weekends ago was the fete de la musique in lausanne. I spent the day listening to various types of music throughout the 36 different stages in the city. There was constantly music being played at every point in the city of every genre. Afterward, I went out and experienced the true nightlife of Lausanne and went out to a bar/dance club until closing time at 5:00 am. This is atypical of what I am used to, coming from Utah, since all bars and clubs are closed at 2:00 am at latest, some are earlier. There is also a much larger variety of music played in the clubs here compared to the clubs in Utah. I think I could get used to the night life in Switzerland :).
This week marked the beginning of the Montreux Jazz Festival. Being a fan of Jazz music, I have found myself grinning for hours on end while listening to the musicians playing on the various stages. I will not be going to any of the concerts which are not free seeing as how the price of each ticket is over $200 in most cases. Aside from the music, there are booths of souvenirs and food for nearly a mile down a walkway, on the way toward Chateu de Chillon (which is worth seeing!!) if you go by foot from Montreux. There are people on the side playing music or painting, and are quite entertaining to observe. I watched some guys make complete paintings using spray paint and paper, no brushes... and they turn out incredibly good! The festival goes until the 19th of July, and I recommend going for at least one night! After the bands are done for the evening (around 12:30-1:00) DJ's take the stage at local clubs (like the MDH club and Montreux Jazz Cafe) and play music until 5:00 am. The first night out I stayed until they closed, last night I came back to Lausanne early (at 3:00) so i would be refreshed enough to go on a hike today in Noiraigue, which has some terrain that is supposed to resemble the grand canyon. Unfortunately, It was raining incredibly hard this morning so I decided not to go this weekend. Even now as I am typing this I can hear drums from the music festival which is simultaneously going on in Lausanne. Switzerland is quite the eventful place in the summer!!